Evolution of viscoelastic coagulation testing

ABSTRACT

Introduction

The methods of viscoelastic coagulation testing (VCT) have evolved since the original invention of thrombelastography over 60 years ago, and new generations of devices are clinically used to guide hemostatic interventions at bedside. The utility of VCTs has been demonstrated in several clinical trials, but diagnostic performance of VCT may vary between devices, various transfusion algorithms, and patient populations.

Areas covered

Working principles and currently available data on the evolving VCTs for coagulation monitoring in acute care settings are reviewed. The PubMed database was used to search pertinent retrospective, prospective, and meta-analysis data on VCTs.

Expert opinion

Point-of-care VCTs provide clinically useful information on platelet count, fibrin polymerization, and other procoagulant factor activities in acute bleeding due to trauma or major surgery, and antithrombotic therapy. The addition of fibrin-specific VCT channel has brought renewed attention to early correction of fibrinogen deficiency using fibrinogen-rich component therapy, and stabilization of fibrin with antifibrinolytic agents. Normal reference ranges vary between devices, and diagnostic and treatment algorithms should be specifically established for each device and indication. There is interest in utilizing VCTs in complex coagulation management relating to hemophilia with inhibitors, but the standardized protocol has not been established.

KEYWORDS:

• Bleeding
• coagulopathy
• direct oral anticoagulant
• hemodilution
• cardiopulmonary bypass
• surgery
• trauma
• viscoelastic coagulation testing
• warfarin

Article Highlights box

• VCT devices measure the onset of whole blood clotting, measure of clot stability, and if any, systemic fibrinolysis with a short turn-around time

• Working principles and normal reference ranges are different between devices

• Effectiveness of VCT depends on the target population, threshold values for intervention, choice and timing of hemostatic interventions

• Sensitivity and specificity of VCTs to warfarin and DOACs are activator reagent-dependent

• Further reagent standardizations are needed to make VCTs useful in monitoring hereditary bleeding disorders

Acknowledgments

The authors wish to thank T Allen & F Viola (HemoSonics), S MacNab (Instrumentation Laboratory, Bedford, MA), and T Taketomi (Nozaki-Tokushukai Hospital, Osaka, Japan) for their expert technical advice and assistance in the manuscript preparation.

Declaration of interest

K Tanaka and R Henderson participated in clinical validation studies sponsored by Instrumentation Laboratory (Bedford, MA), and HemoSonics (Charlottesville, VA). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.